Centrifugal casting core support device having pivotal claw means

ABSTRACT

Core support device for a centrifugal pipe-casting machine. The device comprises a housing having a nonrotating part and a rotating part which is connected to a support ring through at least one branch. The nonrotating part carries a piston-andcylinder fluid motor whose piston rod extends through the nonrotating part of the housing and carries at one end a coreseizing device which is capable of engaging the inner face of the core and is rotatable on the piston rod. The core-seizing device comprises spring-biased pivotal claws which are pivoted to the core-engaging position by abutment of heel portions of the claws against the support ring.

United States Patent lnventor Pierrel Michel Pont-A-Mousson, France Appl. No 51,859 Filed July 2, 1970 Patented Oct. 12, 1971 Assignee Centre De Recherches De Pont-A-Mousson Pont-A-Mousson, France Priority July 3, 1969 France 6922530 CENTRIFUGAL CASTING CORE SUPPORT DEVICE HAVING PIVOTAL CLAW MEANS 5 Claims, 5 Drawing Figs.

US. Cl 164/397, [64/292, 164/340 Int. Cl .t B22e 13/10 Field of Search 164/ 397, 302, 292, 340

[56] References Cited UNITED STATES PATENTS 3,509,938 5/1970 Pierrel 164/302 X FOREIGN PATENTS l,092,6l3 11/]954 France 164/302 Primary ExaminerRobert D Baldwin Attorney-J. Delattre-Seguy ABSTRACT: Core support device for a centrifugal pipe-casting machine. The device comprises a housing having a nonrotating part and a rotating part which is connected to a support ring through at least one branch. The nonrotating part carries a piston-and-cylinder fluid motor whose piston rod extends through the nonrotating part of the housing and carries at one end a core-seizing device which is capable of engaging the inner face of the core and is rotatable on the piston rod. The core-seizing device comprises spring-biased pivotal claws which are pivoted to the core-engaging position by abutment of heel portions of the claws against the support ring.

PATENTEI] nun 21971 SHEET 2 UF 2 3 .4% mm A M d 1W/ CENTRIFUGAL CASTING CORE SUPPORT DEVICE HAVING PIVO'IAL CLAW MEANS The present invention relates to moulds for centrifugally casting iron pipes having a socket and more particularly to the support for the core which produces the internal shape of the socket.

It is known that moulds of this type comprise a core which is adapted to be rapidly placed in position before each casting, perfectly centered in the mould, and capable of rotating at the same speed as the latter, the core being mounted on a support which comprises a core carrier and a nonrotating connecting part or stand.

The core is destroyed when the cast pipe is extracted and is therefore replaced after each casting.

According to known embodiments, the core carrier comprises means for centering the core in the mould and locking means for firmlymaintaining the core in position, while the mould rotates at high speed, so as to resist the pressure of the liquid iron.

Devices are also known for maintaining the core on a corecarrying head in the form of a locking device having a bayonet arrangement comprising screwheads which project from the head and are engaged in corresponding grooves in the core when the latter is rotated.

An object of the invention is to provide a support device for a socket core of a centrifugal casting mould which permits the core to be immediately placed in position by a mere thrust without rotation and its introducing in the centrifugal casting mould.

The invention provides an improved support device mounted at the end of a pivotal arm and comprising a housing having a nonrotating part and a rotating part extended by at least one arm which carries at a distance from the housing a support ring constituting a core carrier, wherein the nonrotating part of the housing carries a jack or piston-and-cylinder device whose rod axially extends through said nonrotating part and core-seizing means journaled at the end of said rod for engaging the interior of the core, said means including pivotal claws provided with heels which, by abutment against said support ring, automatically pivot the claws to the corehooking position.

Thus, in order to fix the core to the ring, it is sufficient to present this core in front of the ring while the cylinder device is in the withdrawn position and then supply fluid to the cylinder device while the core is temporarily held in position manually so that the claws, on an extension of the cylinder device, take hold of the core and are substituted for the manual holding.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings.

In the drawings:

FIG. I is a partial diagrammatic sectional view of a centrifugal casting mould equipped with a support according to the invention;

FIG. 2 is a diagrammatic longitudinal sectional view of the support device, on an enlarged scale;

FIG. 3 is an end elevational view of the device shown in FIG. 2;

FIG. 4 is a partial view, similar to FIG. 2, of the support device carrying the core in a position spaced away from the mould, and

FIG. 5 is a view similar to FIG. 4, the device being in the position for maintaining the core in the mould.

In the illustrated embodiment, the invention is applied to a mould or shell M rotatably mounted inside a fixed case A of a centrifugal casting machine of known type.

The mould M comprises,adjacent the socket of the pipe T to be cast, a bell-shaped flared cavity I (FIGS. 1, 4 and 5) in which is placed in POSITION A CORE N which produces the internal shape of the socket of the pipe T. The hell 1 opens to the exterior by way of a frustoconical tapered portion 2 connected to the bell-shaped part of the socket l by a shoulder 3.

The core N has a flange 4 adapted to arrest the liquid iron and form the end face in the socket E of the pipe. The periphery of the flange 4 is applied against the annular shoulder 3.

The core support device S according to the invention is carried in the known manner (see in particular applicant's French Pat. No. 1,452,172) by an ann B which is carried by a shaft D whose axis is parallel to the axis X-X of the mould. The arm B can be rotated a fraction of a rotation about the axis of the shaft D by a first jack or piston-and-cylinder device V. Another jack or piston-and-cylinder device W causes the shaft D to slide in a direction parallel to the axis X-X so as to shift the arm B toward or away from the mould.

The core support device S comprises a nonrotating housing comprising two coaxial sleeves 5 and 6 which are interconnected by flanges 7 and 8, the outer sleeve 5 being fixed to the arm B.

A third rotary sleeve 9 coaxial with and interposed between the two sleeves 5 and 6 bears axially against the sleeves 5 and 6 through a thrust bearing 10. The sleeve 9 is rotatably mounted by the thrust bearing 10 and a journal rolling bearing 11 interposed between the sleeves 5 and 9.

Fixed to the sleeve 9 is at least one and preferably a plurality of longitudinal arms 12. Rigidly secured to this arm or arms is a ring 13 constituting a core carrier head. The ring 13 has a plane end face 14 and a frustoconical outer face 5 which is complementary to the inner face of the tapered portion 2 of the mould M.

Fixed to the flange 8 of the inner sleeve 6 is a cylinder I6 of a double-acting jack or piston-and-cylinder device. The piston rod 17 of the jack extends axially through the assembly comprising the housing and its end located between the sleeve 9 and the ring 13 carries a member 18 which is rotatable and prevented from axial movement on the rod by a screw 19 engaged in an annular groove 20 in the rod (FIG. 2). Mounted on the lateral faces of the member 18 are claws 21 constituted by cranked levers each of which is pivotable about a pin 22 carried by a lug 23 fixed to the member 18. Springs 24 located in apertures 25 in the member 18 bias the claws in such manner that their arms 26 are at rest roughly parallel to the axis XX. Each arm 26 carries at its end a screw or pin 27 having a point and adapted to take hold of the core. Each claw comprises a heel 28 which extends radially outwardly a distance sufficient to extend over the rear face 29 of the core carrier ring 13 in axial projection.

The device operates in the following manner:

With the cylinder device 16 in the withdrawn position (FIG. 2) and the arm B pivoted by the rotation of the shaft D to the laterally withdrawn position relative to the axis X-X of the mould M of the casting machine, the core N is placed in front of an in axial alignment with the ring 15 so that the flange 4 of the core bears against the front face 14 of the ring. While the core is temporarily held manually in this position the device 16 is supplied with fluid under pressure so as to cause the claws 21 to enter the core N. The heels 28 of these claws abut the rear face 29 of the ring 13 a little before the end of the travel of the rod I7 toward the left (see the positions shown in FIGS. 2 and 4) and these claws 21 are pivoted. The portions 26 of the claws 21 spread apart and the screws 27 engage the inner face of the core N in a region in which the latter is thick and strong. The core is now held in position.

It will be observed that regulation of the screws 27 permits adjustment'in the centering of the core relative to the mould.

Under the action of the device V, the am B then pivots about the axis of the shaft D so as to bring the core support device S on the axis X-X of the mould (FIG. 4). The device W then shifts the assembly of the support S and core N toward the left (compare the positions shown in FIGS. 4 and 5) and drives the ring 13 carrying the core into the tapered portion 2 of the mould M, the flange 4 of the core abutting the shoulder 3 of the mould. As soon as the flange 4 of the core is clamped between the ring 13 and the shoulder 3 of the mould M, the device 16 is once more actuated in the opposite direction so as to withdraw the claws 21 which, under the action of return springs 24, move inwardly and assume an inoperative position of rest.

When the mould M starts to rotate, it drives the assembly consisting of the core N, the ring 13 and the sleeve 9 (the core N is in close contact with the mould M through the circular shoulder 3) and the ring 13 continues to urge the flange 4 against the shoulder 3 and the sleeve 9 is driven by the arms 12.

Note that if iron splashing occurs, in the course of centrifugal casting, through the spaces between the flange 4 of the core and the mould M or through the inner cavity of the core, these splashes can spurt in the space defined between the head 13 and the housing, between the arms 17. The splashes of iron therefore cannot damage and block the core support device S.

After solidification of the cast pipe, the device W shifts the device S away from the mould and the arm B pivots in such manner as to become withdrawn from the axis X-X of the mould M.

The pipe can now be extracted and the device S is ready to receive a core for the following pipe-casting operation.

Owing to the arrangement according to the invention, the inner claws 21 result in a very rapid and ready positioning of the core N on its support and a reliable gripping and introduction of the core into the mould M.

Owing to the withdrawal of the claws 21 after introduction of the core in the mould (FIG. the core is freely and perfectly centered in the mould M by its flange 4 engaged in the portion 2.

Owing to the rotatable mounting of the claw-carrying support 18 on the rod 17 of the device 16, these claws can rotate with the core N. This enables the core to be inserted with no loss of time, even if the mould M is rotating.

Another advantage of the invention resides in the fact that the screws 27 engage internally on the core N in a strong part of its wall so that there is no danger of harming the core, even if it is fragile, such as when it is of sand.

This manner of engaging the core N by means of the screws 27 applies to cores of any material whether mineral (sand), metal, organic (plastics) or other material.

Note that instead of a hooking screw 27 there could be provided a tab or finger attached to or integral with the branch 26 of the claw.

Having now described my invention what I claim and desire to secure by Letters Patent is:

l. A support device fora socket core of a centrifugal casting mould, said device being mounted on an end of a pivotal arm and comprising a housing having a nonrotating part and a rotating part, at least one branch extending said rotating part and carrying at a distance from said housing a support ring constituting a carrier for said core, said nonrotating part of said housing carrying a fluid motor having a slidable member responsive to fluid pressure in said motor, said member extending through said nonrotating part, and core-seizing means journaled on said member adjacent one end of said member for engaging the interior of the core, said core-seizing means including pivotal claw means for hooking said core and having heel portions which are capable of abutting said support ring and automatically pivoting said claw means to a core-hooking position when said slidable member is shifted toward said support ring by said fluid pressure.

2. A support device according to claim I, wherein said coreseizing means comprise a claw means carrier which is journaled on said end of said slidable member, each claw means comprising a cranked lever which is pivoted to said claw means carrier and has a first branch carrying a hooking member for hooking the inner face of the core and a second branch extending outwardly in a substantially radial direction relative to said mould and having such length that it is capable of encountering said support ring and constituting said heel portion.

3. A support device according to claim 2, wherein resiliently yieldable means are interposed between each of said levers and said claw means carrier so as to bias said hooking members in a direction away from said inner face of said core.

4. A support device as claimed in claim 2, wherein said hooking member carried by each cranked lever is an adjustable screw having a pointed end capable of engaging said inner face of said core.

5. A support device as claimed in claim 1, wherein said fluid motor comprises a cylinder and a piston slidable in said cylinder in response to fluid pressure, said slidable member being a piston rod connected to said piston. 

1. A support device for a socket core of a centrifugal casting mould, said device being mounted on an end of a pivotal arm and comprising a housing having a nonrotating part and a rotating part, at least one branch extending said rotating part and carrying at a distance from said housing a supporT ring constituting a carrier for said core, said nonrotating part of said housing carrying a fluid motor having a slidable member responsive to fluid pressure in said motor, said member extending through said nonrotating part, and core-seizing means journaled on said member adjacent one end of said member for engaging the interior of the core, said core-seizing means including pivotal claw means for hooking said core and having heel portions which are capable of abutting said support ring and automatically pivoting said claw means to a core-hooking position when said slidable member is shifted toward said support ring by said fluid pressure.
 2. A support device according to claim 1, wherein said core-seizing means comprise a claw means carrier which is journaled on said end of said slidable member, each claw means comprising a cranked lever which is pivoted to said claw means carrier and has a first branch carrying a hooking member for hooking the inner face of the core and a second branch extending outwardly in a substantially radial direction relative to said mould and having such length that it is capable of encountering said support ring and constituting said heel portion.
 3. A support device according to claim 2, wherein resiliently yieldable means are interposed between each of said levers and said claw means carrier so as to bias said hooking members in a direction away from said inner face of said core.
 4. A support device as claimed in claim 2, wherein said hooking member carried by each cranked lever is an adjustable screw having a pointed end capable of engaging said inner face of said core.
 5. A support device as claimed in claim 1, wherein said fluid motor comprises a cylinder and a piston slidable in said cylinder in response to fluid pressure, said slidable member being a piston rod connected to said piston. 